I have considered this issue long and hard, but I am a little stumped. Therefore, I asked my friend who has had more experience to write this response.
From BLANCHXXX:
Honey, there is nothing you can ever do to make these people stop being jealous of you. No matter what they say or how they think, that is what they are. It is the nature of the beast to crave what it cannot have, say a cake in this instance, and they believe you are having a piece of every cake in the bakery. Not being able to eat cake makes them extremely jealous. Thus, they will say mean and spiteful things to hurt you just to make themselves feel better about it.
Because, if there is something wrong with you, there can't possibly be something wrong with them. When it comes to cake, you must be a little piggy. That way, if they can't have cake, then it isn't their fault.
What they don't realize is that no one has as much sex as they think you are having. No one.
As for your relationship with this boy, it is perfectly natural to be doing what you are. It's very understandable why things didn't work out. Unfortunately, now it seems that the sex part is all you are interested in. While this doesn't make you a slut per se, it doesn't give you much credibility in their eyes either.
I believe the correct term for you would be 'Sexually Liberated'. Which just means you can have sex with a man without attachments or feeling guilty about it. Men have always been sexually liberated, but if a woman even attempts to express her sexuality, why, she must be a slut. While I'll agree some women are sluts, not all women who have sex are! The reverse is not usually true. Men are dogs, they'll do it with anything with a hole, and I do mean anything.
You're a woman. It's your body. You can sleep with whomever you want, damn it! To hell with their opinion, do what you feel is appropriate.
If you really do want a relationship with this boy, tell him that. Say, you think the sex part is really great, but you want something more to go along with it. Then, if he sticks around and is willing to give it a shot, you stick with that. Cut back on having sex, and see how he reacts. If he seems to lose interest in you after that, then there was never a relationship.